Answer:
The skier's change in velocity is 7.69 meters per second.
Explanation:
The Newton's second law tells force is equal to the change on the linear momentum of a body:
[tex]\sum\overrightarrow{F}=\frac{d\overrightarrow{p}}{dt} [/tex]
If we approximate the differential [tex] \frac{d\overrightarrow{p}}{dt} [/tex] to [tex] \frac{\Delta\overrightarrow{p}}{\Delta t} [/tex]:
[tex]\sum\overrightarrow{F}=\frac{\Delta\overrightarrow{p}}{\Delta t} [/tex]
Using that linear momentum is mass times velocity:
[tex]\sum\overrightarrow{F}=\frac{m\Delta\overrightarrow{v}}{\Delta t} [/tex]
Solving for [tex] \Delta\overrightarrow{v}[/tex]:
[tex]\Delta\overrightarrow{v}=\frac{\Delta t\sum\overrightarrow{F}}{m}=\frac{(20\,s)(25\,N)}{65\,kg} [/tex]
[tex]\Delta\overrightarrow{v}=7.69\,\frac{m}{s} [/tex]
